Reseting the bone roll value to 0
I couldn't find which version of Blender had the option to clear when calculating roll, however this seems like it is something Blender should be able to do.

Added http://developer.blender.org/rB2177f645855c242399f3d3324f4d8e0357c3601c

Access from the armature roll menu, or by pressing Alt-R.